Copending U.S. patent application Ser. No. 09/096,663, filed Jun. 12, 1998, by Leroy G. Krupke, et al. and assigned to the assignee of the present invention is directed to an improved torsion spring operated counterbalance system for an upward acting door. The counterbalance system described in the above referenced patent application is particularly advantageous with regard to the arrangement of the torsion springs being disposed within protective tubes which also form part of a spring anchor and winder mechanism.
In the further development of a counterbalance system, generally of the type disclosed and claimed in the above-referenced patent application, it was determined that certain improvements in the winder mechanism, including the manner in which the winder mechanism is connected to the system support brackets and the manner in which the spring protective winder tube is connected to the winder mechanism, was desirable. For example, a mechanically uncomplicated arrangement of the winder mechanism to include a minimum number of parts was deemed desirable. Still further, the manner in which the winder mechanism is connected to stationary support structure to form an "anchor" for the torsion coil springs was also deemed to require, or at least be desirably provided with an easier to install structure. As always, improvements are sought which will reduce manufacturing costs while, at the same time, provide a suitable or desirable structure which may be easily installed and serviced and is reliable in operation. It is to all of these ends that the present invention has been developed.